Answer:
The frequency heard y the ship is 70 MHz.
Explanation:
True frequency, f = 50 MHz
speed of source, vs = 0
speed of observer, vo = 0.4 c
Let the frequency heard by the ship is f'.
Use the formula of doppler's effect

Answer:
You need to know the accuracy to which you can read the ruler:
Suppose that you can read the read the ruler to the nearest milimeter
A = L * W your calculated area of the rectangle
A + ΔA = (L + ΔL) * (W + ΔW) = L W + L ΔW + W * ΔL + ΔL ΔA
Or ΔA = L ΔW + W ΔL
Where we have subtracted A = L * W and the term ΔL * ΔA is very small
So (5 + .1) * (2 + .1) - 5 * 2 = .1 * 2 + .1 * 5 = .7 cm^2
Then you report A = 10 cm^2 +- .7 cm^2 including the - sign for completeness
Answer:
Average speed in east direction
Explanation:
We have given average speed of the entire trip = 5 km/hr
First the car 4 hours then travels 12 km in 4 hours
So total time of the trip = 4+4 = 8 hours
So total distance traveled in the trip 
As the car travel 12 km in 4 hours to the west
So distance traveled in 4 hour in east = 40 -12 = 28 km
Time in east direction = 4 hour
So average speed in east direction 
Answer: The smallest effort = 300N
Explanation:
Using one of the condition for the attainment of equilibrium:
Clockwise moment = anticlockwise moments
900 × 1 = 3 × M
Where M = the weight of the strong man
3M = 900
M = 900/3 = 300N
Therefore, 300N is the smallest effort that the strongman can use to lift the goat
( 3 yr) · (186,282.397 mile/s) · (86,400 s/day) · (365 day/yr)
= (3 · 186,282.397 · 86,400 · 365) mile
= 1.762380502 x 10¹³ miles
= 1.8 x 10¹³ miles (rounded to the nearest trillion miles)